1. Field of the Invention
The present invention relates to data storage systems for multidimensional parity protection, and more particularly to data storage systems for multidimensional parity protection which may be created independently of existing systems and which may be created to be retrofittable to existing multiple drive disk systems. The invention includes a housing containing a plurality of parity disk drives for guarding data stored on conventional data disk drives with means for data reconstruction of data from conventional disk drives such that a multidimensional, mirrored, orthogonal parity array is established.
2. Information Disclosure Statement
The following patents describe the state of the art in relevant data storage systems:
U.S. Pat. No. 5,271,012 to Blaum et al. teaches a method and means for encoding data written onto an array of M synchronous DASDs and for rebuilding onto spare DASD array capacity when up to two array DASD fail. Data is mapped into the DASD array using an (Mxe2x88x921) *M data array as the storage model where M is a prime number. Pairs of simple parities are recursively encoded over data in respective diagonal major and intersecting row major order array directions. The encoding traverse covers a topologically cylindrical path.
U.S. Pat. No. 5,351,246 to Blaum et al. teaches a method and means for coding an (Mxe2x88x921) *M data array written onto an array of M synchronous recording paths and for rebuilding and writing onto spare recording path capacity when up to a preselected number R of array DASDs fail, or one DASD becomes erroneous and up to Rxe2x88x922 fail. Data is mapped into the parallel paths using and (Mxe2x88x921)*M data and parity block array as the storage model where M is a prime number and each block extent is uniform and at least one bit in length. The (Mxe2x88x921)*M data and parity block array is encoded to include zero XOR sums along a traverse of slopes 0,1,2, . . . , Pxe2x88x921, extended cyclically over the data array.
U.S. Pat. No. 5,412,661 to Hao et al. teaches a data storage system architecture having an array of small data storage disks, organized into logical rows and columns, with each disk coupled to two disk controllers via two independent controller-disk interconnects. No two disks are coupled to the same pair of controllers. The component disks are arranged in parity groups of variable size. Within each parity group, failure of one disk sector can be recovered through data reconstruction using data from other disks in the parity group. One or more of the disks can be reserved as hot standbys for substitution on failure, automatically replacing any failed disk.
U.S. Pat. No. 5,572,659 to Iwasa et al. teaches an adapter connected between a host computer and disk storage devices providing interfaces for connecting to the host computer and the disk storage devices having the same interface design. The adapter includes control means for building a redundant disk storage system and includes means for detecting and indicating a failed disk storage device, means for replacing the failed disk storage device and means for rebuilding a redundant disk storage system after the replacement of disk storage devices.
U.S. Pat. No. 5,544,339 to Baba teaches an array of disk drives for storing information which is accessed through multiple channels by a host computer. Different channels are coupled to different sequences of disk drives. Different disk drives can be accessed simultaneously through different channels, enabling high data transfer rates. The same disk drive can be accessed through two different channels, enabling access even if one of the channels is busy or malfunctioning. In one case, the channels are divided into at least two mutually exclusive sets of channels, each set providing access to all of the disk drives.
A text by Garth A. Gibson and David A. Patterson entitled, xe2x80x9cDesigning Disk Arrays for High Data Reliabilityxe2x80x9d, a text by Peter M. Chen and Garth A. Gibson entitled, xe2x80x9cRAID-II: A High-Bandwidth Network File Serverxe2x80x9d, a text by Garth A Gibson and Jeffrey Scott Vitter and John Wilkes entitled, xe2x80x9cReport of the Working Group on Storage I/O for Large Scale Computingxe2x80x9d, a text by Garth A. Gibson entitled, xe2x80x9cRedundant Disk Arrays, Reliable, Parallel Secondary Storagexe2x80x9d and a text by Garth A. Gibson, Lisa Hellerstein, Richard M. Karp, Randy H. Katz and David A. Patterson entitled, xe2x80x9cCoding Techniques for Handling Failures in Large Disk Arrays,xe2x80x9d describes various types of storage protection and secondary disk arrays.
Notwithstanding the foregoing, the prior art neither teaches nor suggests a data storage system for multidimensional parity protection including for retrofit or use with a plurality of conventional disk drives for storing data wherein each of the conventional data disk drives is symmetrically linked to at least three parity disk drives for guarding data stored on the data disk drives, as taught by the present invention.
A data storage system for multidimensional parity protection includes a housing for containing a plurality parity disk drives for guarding data stored on a plurality of conventional data disk drives. Each of the conventional data disk drives are connected with the parity disk drives so as to create a multidimensional parity relationship in excess of two dimensions, with the plurality of parity data disk drives such that a multidimensional, mirrored, orthogonal parity array is established. The data storage system further includes a failure detection component coupled to the three dimensional, mirrored, orthogonal parity arrays for detecting and indicating the failure of any disk in the mirrored, orthogonal parity arrays. In addition, a data reconstruction component is coupled to the three dimensional, mirrored orthogonal parity arrays for reconstructing data from any failed disk by combining data from other parity disks in the orthogonal parity arrays.